Bisphenol A is a monomer used in the manufacture of polycarbonate plastic products, epoxy resin-based food can liners and flame retardants. To determine the genotoxic potential of bisphenotA, the mechanism of the reactions between the reactive electophilic bisphenol A 3,4-quinone (BPAQ) with glutathione and ribonucleosides/deoxyribonucleosides were studied. The obtained results demonstrated that BPAQ reacted with 2'-deoxyguanosine (dG)/guanosine (G), 2'-deoxyadenosine (dA)/adenosine (A), but not with 2'-deoxycytidine (dC)/cytidine (C) and thymidine (T)/uridine (U) in aqueous acetic acid. The reactions were accompanied by loss of deoxyribose, and the rate of depurination by deoxyribonucleoside adducts were faster than that of ribonucleoside adducts. In mixtures of ribonucleosides and deoxyribonucleosides treated with BPAQ, reactions occurred more readily with dG/G than dA/A. The structures of the modified bases were confirmed by electrospray ionization tandem mass spectrometry (ESI-MS/MS). We also found that BPAQ reacted readily with glutathione (GSH) in aqueous acetic acid, and characterized the BPAQGSH conjugate by ESI-MS/MS. The in vitro data of depurinating DNA/RNA adducts and BPAQ-GSH adducts may provide appropriate reference for the identification of BPAQadducts in environmental and biological systems. (C) 2016 Elsevier B.V. All rights reserved.